Time-series forecasts are used in a wide range of
economic activities, including setting monetary and
®scal policies, state and local budgeting, ®nancial
management, and ®nancial engineering. Key elements
of economic forecasting include selecting the fore-
casting model(s) appropriate for the problem at hand,
assessing and communicating the uncertainty asso-
ciated with a forecast, and guarding against model
instability.